For reasons explained in chapter 3 of "Auditory Neuroscience", cochlear implants do a very poor job at conveying musical pitch. Consequently, cochlear implant users can get the rhythm of a piece of music, but have tremendous difficulty recognizing or appreciating melodies. Their enjoyment of music is sadly much diminished as a consequence.
Here we again use noise vocoding to simulate what the world sounds like through a cochlear implant, but this time, instead of a speech sample, we run the noise vocoder over a short snippet of music.
The piece we use for this illustration is a short extract of Ludwig van Beethoven's"Kreutzer Sonata", a very sophisticated piece for piano and solo violin. Beethoven himself famously became deaf, losing his hearing in adulthood. The cause of his deafness is uncertain. Nowadays he would be eligible for cochlear implantation, but while that would have restored his ability to understand speech in quiet, it would have done little to facilitate his work with music, as you may appreciate when you compare the normal extract of the Kreutzer Sonata with the vocoded ("cochlear implant filtered") one. In the vocoded example, the melody is almost completely lost, and it is similarly very hard to make out which instrument is playing when.
Kreutzer Sonata - normal:
Kreutzer Sonata - vocoded: